This invention relates to a disposable dental handpiece, and more particularly to a disposable right angle dental prophylaxis handpiece.
Disposable dental prophylaxis right angle hand pieces are known, for example, from U.S. Pat. No. 3,727,313, the entire contents of which are incorporated herein by reference. Such disposable dental handpieces are desirable since the portions that come into contact with a patient may be thrown away after use, thereby eliminating the expense of sterilizing the handpiece and also eliminating the risk of incomplete sterilization and/or transfer of infection. At present, the transfer of infection is of utmost concern.
The disposable right angle hand piece of U.S. Pat. No. 3,727,313 is disadvantageous in that all of the internal parts thereof are made of disposable plastic materials, and thus the device provides poor operability. The shaft itself is made of plastic and provides poor engagement with the drive mechanism. Moreover, plastic particles wear off the shaft and cause damage to the internal parts of the handpiece and may also possibly damage the drive mechanism of the dental equipment. The plastic gears are inferior and provide poor power transmission between the drive shaft and the elastic rubber working cup 24. Also, the plastic gears tend to wear during use, even for a short time.
The object of the present invention is to provide an improved disposable right angle prophylaxis handpieces which has improved operability, which overcomes the disadvantages inherent in the design of known devices such as that disclosed in U.S. Pat. No. 3,727,313.